United States · Montana · Deer Lodge
Montana State Prison
Data is aggregated from public sources and may be incomplete or out of date. Always verify with primary sources before acting on any figure. See data sources.
For families
How to send mail, money, and visit Montana State Prison
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Gallery
From Wikimedia Commons (CC-BY-SA where not otherwise stated).
Photo by Tanankyo via Wikimedia Commons (Public domain)
Photo by simpleinsomnia via Wikimedia Commons (CC BY 2.0)
Photo by SGT141 via Wikimedia Commons (Public domain)
Photo by Montanabw via Wikimedia Commons (CC BY-SA 3.0)
Photo by Montanabw via Wikimedia Commons (CC BY-SA 3.0)
Photo by simpleinsomnia via Wikimedia Commons (CC BY 2.0)
Photo by Tanankyo via Wikimedia Commons (Public domain)
Photo by Tanankyo via Wikimedia Commons (Public domain)
Montana State Prison is a state prison located in Powell County, Montana. Rated capacity: 1,495. Reported population: 1,550. Security level: Maximum. Data sourced from the HIFLD Prison Boundaries open dataset.
Background
The Montana State Prison is an American men's correctional facility of the Montana Department of Corrections in unincorporated Powell County, Montana, about 3.5 miles (5.6 km) west of Deer Lodge. The current facility was constructed between 1974 and 1979 in response to the continued degeneration of the original facility located in downtown Deer Lodge. The "Old Prison" (46°23â²33â³N 112°44â²10â³W) served as the Montana Territorial Prison from its creation in 1871 until Montana achieved statehood in 1889, then continued as the primary penal institution for the State of Montana until 1979. Throughout the prison's history, the institution was plagued with constant overcrowding, insufficient funds, and antiquated facilities. The administration of Warden Frank Conley from 1890 to 1921 proved the exception to this rule, as Warden Conley instituted extensive inmate labor projects that kept many inmates at work constructing the prison buildings and walls as well as providing various state and community services like road building, logging, and ranching.
Source: Wikipedia article lead, CC-BY-SA.
Capacity
1,495
Current population
1,550
Occupancy
104%
Year opened
1886
Operational
Figures from official sources · verified 2 Jun 2026 · methodology
Facility profile
Population held
Mixed/unknown
Opened
1886
Region
Montana
Security level
Maximum
Death-row facility
No
Conditions
No conditions summary available yet.
Visiting
No visiting information available.
Mailing
No mailing information available.
Practical info
Contact the operator's website for inmate-specific procedures.
Known issues
No major issues documented in our database.
Contact & address
Conditions Risk Score
Derived signal — not a judgement. How it's calculated
- Overcrowding
- 5/30
- Oversight reports
- 0/30
- Structural flags
- 0/15
- Death signals
- 0/15
- Conditions text
- 0/10
What the score is responding to:
- · Operating at 104% of design capacity
This facility scores 5. The national average across 7,437 scored United States facilities is 2 — 3 points above national average.
Related facilities
Same country, matched on type + security level where possible.
- Woodman State JailGatesvilleMaximumState prison720% occupancy
- Centinela State Prison (Cen)ImperialMaximumState prison150% occupancy
- Kern Valley State Prison (Kvsp)DelanoMaximumState prison152% occupancy
- Diagnostic And Evaluation CenterLincolnMaximumState prison178% occupancy
- High Desert State Prison (Hdsp)SusanvilleMaximumState prison152% occupancy
- Calipatria State Prison (Cal)CalipatriaMaximumState prison161% occupancy
Compared to other facilities in United States
7436 peersData completeness
74%How many of our profile fields are populated. We surface this so families and researchers know the limits.
Sources
- HIFLD Prison Boundaries
- HIFLD dataset query
- Wikipedia — Wikimedia Foundation
- HIFLD Prison Boundaries — US Department of Homeland Security â HIFLD Open Data
- OpenStreetMap — OpenStreetMap Contributors
- Wikidata — Wikimedia Foundation
- Wikidata (Q6904327)
- Wikipedia
- Wikimedia Commons
- See /data-sources for our overall methodology.
Cite this page
Under CC-BY-4.0. Include the URL and access date; the site is a living reference and entries can change.
World Prisons. (2026). Montana State Prison. Retrieved October 28, 2026, from https://worldprisons.com/prisons/montana-state-prison
"Montana State Prison." World Prisons. Accessed October 28, 2026. https://worldprisons.com/prisons/montana-state-prison.
@misc{worldprisons-montana-state-prison,
author = {{World Prisons}},
title = {Montana State Prison},
year = {2026},
url = {https://worldprisons.com/prisons/montana-state-prison},
urldate = {2026-10-28}
}